id,summary,reporter,owner,description,type,status,priority,component,version,resolution,keywords,cc,guest,host
6506,Appliance export is horribly slow,mickler,,"Dear developers,
I am using Debian Lenny 64-bit host system.
I created and installed a Scientific Linux 64-bit guest with dynamic sized hard disk (20 GB max). Now I want to export it using the File->Export Appliance... Wizard. The write speed varies between 500k and 1.5MB per second while reads are occuring intermittently at ~10MB/s (numbers taken from iotop). The progress meter tells me that the remaining time is something about 4 hours.
I think this is a serious performance flaw in VirtualBox... I see roughly the same disk speed if I do dd if=/dev/zero of=somfile bs=1, i.e. writing 1 byte at a time to a file on disk. When using a tmpfs as target for the export, it is reasonably fast - but I don't have enough RAM to use this a a work-around ;-)
If this is of interest - my file systems are XFS and the virtual machine files are under /home/ and export is done to /opt/:
{{{/dev/sda6 on / type xfs (rw,relatime,logbufs=8,logbsize=256k)}}}
{{{/dev/sda7 on /home type xfs (rw,relatime,logbufs=8,logbsize=256k)}}}
Thanks in advance for your help.
Cheers,
Holger",defect,closed,major,other,VirtualBox 3.1.6,duplicate,,,other,Linux